Cutting knife-stack support



Nov. 27, 1956 c. THUMIM 2,771,948

CUTTING KNIFE-STACK SUPPORT A A Filed Dec. 12, 1952 Vffii'.Sheets--Sheet l IVE- E.

Nov. 27, 195e c. THUMIM 2,771,948

CUTTING KNIFE-STACK SUPPORT Filed Dec. 12, 1952 @sheets-sheet 2 IN VEN TOR. 044,4 /'w/Ar firme/V695' y Nov. 27, 1956 c. THUMIM CUTTING KNIFE-STACK SUPPQR?q 4 SheetsfSheet 3 Filed Dec. 12, 1952 IN VEN TOR. 7710,90

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Nov. 27, 1956 c. THUMIM CUTTING KNIFE-STACK SUPPORT 4 Sheets-Sheet 4 Filed Dec. l2, 1952 lll/l IN VEN TOR.

United States Patent CUTTING KNIFE-STACK SUPPORT Carl Thumim, Lansdowne, Pa., assignor to E. P. Lawson Co., Inc., New York, N. Y., a corporation of New York Application December 12, 1952, Serial No. 325,625

4 Claims. (Cl. 164-51) This invention relates to cutting machines of the type which are used for severing heavy stacks of paper sheets, known as guillotine type paper cutters, and more particularly to a novel table which renders manual handling of paper thereon easier and more convenient.

In general, when a stack of paper is to be severed at predetermined lines, each severance requires the entire stack to be moved by the back gauge. Since a stack of paper may weigh upwards of a hundred pounds or more, it will be readily apparent that maneuvering of the paper stack to locate it properly with respect to the back gauge or to remove it from the table is tiring to an operator.

My present invention is intended to reduce the force necessary for sliding or maneuvering a paper pile resting on a cutting machine table and has for its objects the provision of means which are easily manufactured and readily incorporated in a cutting machine.

A further object of my invention is to provide means for minimizing the force necessary to maneuver a pile of paper which means is of a relatively simple nature and usable with aminimum of operating eXpense as well as being rugged and dependable over a long period of time without maintenance and repair diculties.

Briefly, my invention comprises the provision of a plurality of ports in the cutting table surface underlying paper normally stacked thereon. The ports are connected with a source of compressed air controllable either automatically or at the will of an operator and whereby a film of air is forced between the lowermost sheet of the pile and the table surface. The effect is analagous to placing a lubricant film between two heavily engaged surfaces. Thus, the entire pile, heavy though it may be, is much more readily shifted to predetermined positions for cutting purposes below the knife.

Specifically, my construction comprises ports arranged in a symmetrical pattern of generally, but not necessarily, rectangular configuration and having a few inches of spacing between them. Each port is provided with a valve operator element that protrudes slightly above the table surface. When a stack of paper is on the table, the weight thereof is suicient to press down on the operator elements so as to permit egress of air from the respective ports. Thus, compressed air is fed only to ports covered by the paper stack and nds access therethrough to the bottom surface of the paper stack for the purpose set forth.

My invention will now be described in conjunction with the accompanying drawing in which:

Figure l is a side elevational View of a novel paper cutting machine embodying features of the present invention.

Figure 2 is a front elevational View of the paper cutting machine of Figure l showing the back gauge, cable attachment and controlled carriage of the automatic spacer cutting machine.

Figure 3 is a plan view of the machine of Figure 1 showing such elements as are essential to an understanding of the present invention.

Figure 4 is an enlarged fragmentary detail taken alon line 4 4 of Figure 3.

Figure 5 is an exploded perspective view, with parts sectioned, of one of the valves used to control air to the plurality of ports.

Figure 6 is a fragmentary top plan view of a modified table top embodying further features of the present invention.

Figure 7 is a sectional view taken along line 7 -7 of Figure 6 and looking in the direction of the arrows.

Figure 8 is a sectional View taken along line 8-8 of Figure 6 and looking in the direction of the arrows, and

Figure 9 is an electrical diagram showing the mode of connecting certain components of the invention. n

My present invention is illustrated as used in conjunction with a cutting machine having the construction disclosed in the co-pending application of Frederick W. Seybold Iand Nicholas Herman for Automatic Back Gauge Spacer, Serial No. 200,013, filed December 9, 1950, now Patent No. 2,737,158,

Referring now to the drawings, there is shown as much of the construction of the above-identified cutting machine as is necessary to render the description of the present invention clear and lucid. Briefly, the illustrative cutting machine includes a main fratrie F carrying a horizontally extending cutting table T, a vertically displaceable cutting knife K, a paper clamp C arranged rearwardly of the cutting knife K and lowered against the paper lift with pressure prior to cutting and a back gauge G selectively positioned on the cutting table T to move the paper lift into position for cutting. The back gauge G is driven toward and away from the knife K by a lead screw 10 in threaded engagement with an integral head on the back gauge G, the lead screw 10 being coupled to a hand wheel 12 adjacent the forward end of the machine and to a drive motor 14 adjacent the rearward end of the machine.

The operating mechanism for generally moving the back gauge G, the clamp C and the cutting knife K form no part of the present invention and` accordingly their descriptions will be limited to features related to the present disclosure, for the purposes of clarity and simplicity. j

In accordance with the present invention, the table T is provided with a plurality of rows of spaced ports or air exits 29, distributed uniformly about the paper supporting surface 22 of the table T. The number of ports 2t) is selected in accordance with the fioating action required as will subsequently become apparent. The

respective ports are interconnected by internal tubes or passageways 24 in the table T to a common tube or inlet 26 adapted to be connected to a suitable source of air under pressure.

Specifically, an air pump ZS constructed and arranged in accordance with principles well understood per se is connected via appropriate gearing 30 tov a drive motor 32. The high pressure outlet 34 of the pump 28 is connected to a high pressure reservoir 36 and then to a low pressure reservoir'38 via a reducing valve 40. The low pressure reservoir is connected to the air inlet 26 by an electrically operated three-way valve 42 normally closed and illustrated as a solenoid controlled valve having a solenoid plunger 44 arranged in controlled relation relative to the solenoid coil 46.

A suitable source of line potential 48, 48' is provided for the solenoid coil 46 which forms part of a control circuit arranged to coordinate the admission of air to the ports 20 in dependence upon operation of the back gauge G, the clamp C, and the cutting knife K. Specifically,

Patented Nov. 27, 1956 When the clamp Cis brought into contact with the paper prior to operation of the cutting knife K, it is undesirable to admit air to the inlet 24 via the normally closed air inlet valve 42, since this might result in sidewise displace-Y ment 'of the paper upon engagement therewith of 'the clamp C. Accordingly, in circuit with a manual opera-Y tors switch 50, the closing of'which would normally com- Yfore, as the clamp assembly moves fromY the inoperative Vor retracted position illustrated by the full lines of Figure 1 to theV clamping or extended position illustrated by the broken lines, v.the Ilever S rocks in the counterclockwise direction due -to the bias of spring 62 to open the circuit breaker 52.V Since the clamp C moves downwardly just prior to a cutting operation, it follows that air supply to the ports will be precluded during cutting as wellas clamping. Of course, return of the clamp C to the retracted or inoperative position results in a closing of the circuit breaker 52 and return to control by the manual switch 50.

VA further instance when yit is necessary jto preclude air supply to the ports 20 is when the back gauge G is inV motion to position the paper relative to the knife C. At such times, oating of the paper might cause an overtravel of the paper relative to the adjusted position to which the paper is brought by the back gauge G. To obviate this dicultry, a further switch 66 is-connected in the solenoid control circuit, this switch being connected in controlled relation to the back gauge motork 14, i. e., in electrical parallel therewith as shown in Fig. 9, precluding the possibility of activating the solenoid coil 46 when the back gauge G is being adjusted. As a further feature, .the three-Way valve 42 is arranged to open the air inlet 26 to'the atmosphere whenever the supply from the-low pressure reservoir 3S is cut o, thereby releasing any lifting pressure which might be available at the ports 20 of the tableT as a resultof prior introduction of air under pressure to the table T.

Reference Will now be made to Figures 4 and 5 Wherein the details of air release valves for the respective ports on air exits 20 are shown. The purpose of the valvesr70 is to lrelease air only under the paper stack, operation of Vthe valves in predetermined areas of the table T being brought about by the paper being supported thereon. Specifically, each'valve 70 is partially recessed upwardly in a complementary cut-out in the table T and includes an externally stepped bushing 72 having a circular open upper end 74 defining a port 20 and formed with a coaxial ball valve seat V76. Within the bushing 72 is an operator element in the form of a ball valve 78 biased against the seat 76 by a spring 80 bearing against a perforated insert 82 and restrainedY by a split lock ring 84 itting into an annular depression. 86 provided in the bushing 72. As is apparent to those skilled in the art, the diameter of the ball valve 78 is somewhat greater than that of the port dening opening 74. The lower end of the bushing 72 is upwardly and outwardly flared at S8 to receive a .complementary flange 90 on the adjacent air tube 24, a suitableV pressure coupling 92 providing an air-.tight seal therebetween. Accordingly, as the pile properis brought Y into position over a predetermined area of the cutting table T, the weight of the pile will depress the operator ele- -mentsV 78 thereunder to release air through the open ports direction of the .cutting knife shear.V

ing the underlying ball valves 74, thereby avoiding un necessary loss of air at locations which are -not imme- Y diately beneath the pile proper.

In Figures 6 to 8, inclusive, there is shown a modlied table construction in which each of the ports 20 is provided with an air-directing or channeling slot 100 angular'ly related to the position of the cutting knife K and the In the illustrative arrangement of Figure 6, the slots 10G, including inclined floors 100 merging into the table surface, are directed 'Y 'to the kleft at an acute angle relative to the directionY of cutting shear indicated by the arrows A102. Since thecut- Y ting shear of knifeKrwill always tend to Vpushthe'paper against the adjacent side guard 104, therejwill be no waste of air Which is ,likewise directed generally toward the guard N4 and the location of the cuttingknife K.

In the foregoing IY have described my `invention solely in connection with specific illustrative embodiments thereof. vention will now be obvious 'to those skilled in the art,

I prefer to berbound not by the speciiic disclosures hereinY contained but only by the appended claims.

l claim:

l. A cutting machine comprising a table for support- Y ing paper stock to be cut, said table having a plurality of spaced ports for admission of compressed air to the of said back gauge motor.

. In a cutting machine including a table for supporting paper stock to be cut, a clamp and cutting knife i. n Y movable independently toward and away from a sup-.KV porting surface of said table, a back gaugeV adjustable along-said table relative to said knife, said supporting surface being provided with air admission ports adapted to supply an air cushion beneath paper stock supported Y thereover, a valve including a depressible operatingmem-` ber projecting above said supporting surface and normally constricting each of said ports, a source of air under pressure, a conduit system interconnectingy said source and therespective ports, a normally closed, Yelectrically operated, air admission valve in said conduit system, and an energizing circuit for said air admission valve including disabling means operative in response to movement of either said clamp or said back gauge andVV precluding opening of said normally closedy air admis- K sion valve.

andeach including an `operator-element projecting Vabove said supporting surface and arranged to openV said valve means u pon depression by contact with a lquantity of stock on said supporting surface, a source of air Yunder pressure for supplying said ports, and a conduit system Y interconnecting said source and said ports, a clamp movable toward and away from saidV table, a normally closed air control valve in said conduit system, and disabling" means operative in response-to movement of said clamp toward said table for precluding opening of said nor#y mally closed air control valve.

4. A cutting machine comprising a table for supporting paper stock to be cut, said table having a plurality of spaced ports in the supporting Y,surface thereof for egress therethrough of air under pressure, respective valve means normally constricting each of said ports and Y each including an operator element projecting above ksaid supporting surface and arranged to open said valve means upon depression by contact with a quantity of stock on said supporting surface, a source of air under Since many Vvariations and modifications of my inj pressure for supplying said ports, and a conduit system interconnecting said source and said ports, a back gauge adjustable along said supporting surface of said table,

a drive operatively connected to said back gauge for displacing same into an adjusted position, a normally 5 closed air supply control valve in said conduit system, and disabling means operative in response to operation of said drive for precluding opening of said normally closed air control valve.

Wardley Mar. 7, 1933 Flynn et al. May 17, 1938 Duda Mar. 23, 1943 Deans Jan. 2, 1945 Magnani Ian. 23, 1951 Ross Sept. 8, 1953 FOREIGN PATENTS Great Britain 1902 

